GABA and alcohol have mutual functions in the human body. The chief relationship between them is that alcohol has similar effects to those of GABA on the nervous system. This is because alcohol binds to and activates the same receptors that suppress the firing of neurons, which slows down activity in the central and peripheral nervous systems. In alcoholics, normal function of the neurotransmitter GABA becomes dependent on the presence of alcohol in the bloodstream.

The acronym GABA stands for gamma-aminobutyric acid. It is the principal inhibitory neurotransmitter in the brains of humans and all other mammals. When GABA is released by one neuron into a synapse, it binds to GABA receptors on adjacent neurons and prevents these cells from firing by reducing their electrical excitability. Many depressants, including alcohol, can bind to GABA receptors and trigger the same inhibitory response.

Alcohol binds the class of GABA receptor known as GABA-A. These receptors are found throughout the brain in different subtypes, where they moderate neuronal communication by inhibiting signals between neurons. GABA neurons are essential to neurological function, from basic control of breathing and walking ability to vision. Like most sedatives, alcohol increases the inhibitory effects of GABA, which explains why alcohol depresses motor skills and perception.

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GABA and alcohol enhance each other's effects. GABA and alcohol together will have a greater effect than the same amount of alcohol or GABA by themselves. When it binds to GABA-A receptors, alcohol is thought to increase their ion conductance, causing the neuron to become even less excitable. Alcohol also enhances GABA absorption. Combined with other GABA agonists like barbituates, alcohol can increase the sedative effects of these drugs.

Glutamate is the primary excitatory neurotransmitter in the brain, and neurons use it to induce electrical communication between cells. Both GABA and alcohol oppose the effects of glutamate in the nervous system, but GABA does this indirectly by preventing cells from firing. Alcohol opposes glutamate action by binding to glutamate receptors, but not activating them. It blocks the receptor so that glutamate cannot bind to it and excite the neuron. By doing this, alcohol further enhances the inhibitory effects of GABA.

Alcoholism changes the relationship between GABA and alcohol. GABA-A receptors become less sensitive to alcohol, and require larger quantities of it to respond, while glutamate receptors become hypersensitive to even smaller amounts. If an alcoholic enters alcoholism treatment, he or she may experience withdrawal symptoms that reflect the depressed function of GABA receptors that have become dependent on alcohol. Shaking, hallucinations, even violent seizures can result from diminished GABA response and hyperactive glutamate receptors.

Discuss this Article

ZipLinePost 4

I did not know that alcohol causes GABA receptors to act differently. Is the reduction in the sensitivity of GABA receptors the cause for alcohol addiction then?

I've always known that alcohol addiction is a very difficult addiction to overcome. Alcoholics who quit experience many withdrawal symptoms that usually cause them to go back to alcohol. I've heard that sudden withdrawal from these types of addictions can even lead to death.

If GABA and GABA receptors play such an important role in alcoholism. Can doctors use medications to make GABA receptors act differently? I think if something like this could be done, it would be easier for people to stop drinking. Does anyone agree with me?

SarahGenPost 3

@fBoyle-- I'm not an expert on this topic but I think so.

Someone who is depressed probably already has a lot of GABA in their system. So when alcohol is added to that, the central nervous system is going to be depressed even more. This will not only cause emotional issues like feelings of anxiety and depression, but it will also affect breathing, heart rate and motor control as the article said.

One of the biggest risks of using medications like antidepressants and sedatives with alcohol is that the combination may cause respiration to stop. So these types of combinations can lead to death.

Even if someone is not on antidepressants, I think that he will experience more side effects from alcohol if he is depressed. And that's because of GABA.

fBoylePost 2

Is this why the use of alcohol is not recommended while someone is on antidepressants?

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